The Practical Planter

The cassia that can grow in the poorest of soils

By E. G. Brown , Colonial Products Laboratory.

In coming months, PIM will publish articles supplied by the British Government's Tropical Products Institute on the various forms of the spice cassia. This month: Vietnamese cassia

f At l e^ st fou r species of Cinnamomum, yielding aromatic cassia barks of commercial value am and occurs throughout the area, from Upper Tonkin to Cochin China

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tied mountain slopes suit them The best soils are found in tin valleys on the eastern slopes he Annamite range, and consist sd laterite remains of old volcanic ;n, mixed with gravel and clay, laying alluvia, deposits. le rainfall i„ these areas is 100 20 inches; a high rainfall is esal for the production of good ty bark, and it is said that its vanes in direct proportion to quantity of water the tree has /ed - .

Main areas

e tree is propagated by birds, originally only wdd trees were ited, but as the most accessible of the forests became depleted, ation of the tree increased a bark from the trunks of old, trees is regarded as the best. from cultivated trees is cond to be inferior, probably beit is harvested at an earlier age Ihe wild bark. 8 : main producing areas are in m-savage tribe inhabiting the tains of Annam, clear the Hanes 'eeds from groups of bird-sown m the forests, and also plant near their villages Preparation of the bark is

whTb d u y °« y d i b „r.^s A ?rr e t S h e e Mois- they also grow B their own in the plains both n nW.t nn? and in their gardens S?* fruit areca B nuts bananas bushes Most of the Sn d duced inCentral nbtafnS from trts ° btamed The best and most expensive bark, que-thanh, comes from the province of Thanh-hoa in north Annam. Until 1955, the bark from Thanh-hoa had, centuries past, been reserved for the use of the Royal Court at Hue.

Such quantities as reached the market (usually the lower grades not required b y. the court) realised very high slightly lower quality que-auy y ’ tL l ii *l® DUiK The provinces of Quang-nam and Quang-ngai, in the neighbourhood of Tourane in central A?nam arethe source of the bulk of thO’ ordLl™ commercial grades- the bark from

these provinces is’ iSL f. from

fang. Bark of this type is also pmsr&'ii,Tu a ,,,. M .asi m the area around Yen-bay on the Tl Sht bank of the Red River in Tonkin. 6r ’ m r u- , , Cultivation '■ Although the tree can 5

T* “J .—tunes .cans-

Planted, but seed is generally pre ‘ Fruits are elected from healthy vigorous trees at least 15 ? d ’ lth strai B ht trunks and ba £ ° f good colour - ? nUtS are Soaked in water and ru ll bbed "l d washed vSitv in about T"SSJSh. their dried in the shade anH°' D 8h d’ + a [ e sown in fine Ln talTe” place kfter ten tn f* r ' nmatlon in central Annam dayS weeS in Tonkin ’ C t 0 S ‘ X r r ■■

Carefully

February S ° Wn “• Ja " uary or vo„n» , Af r Summation the young plants are kept shaded with straw mats, the shading being gradually reduced to accustom the

AwtS full , sufhine

thl • u °t i year the P lants tta J n a . height of about 3f t and are ready f ° r tran ?P la nting into their pern J a {J ent positions; they are lifted carefully “> Prevent damage to the interVa ' S W °< the fost two or months during five of S ee learI ears > and every r . SIX T months afterwards. Once a year, in January, the lower branches are cu * dose to the trunk.

mam, are thinly populated and en densely forested. The trees have be searched for, and are recognised their strong, characteristic odour. fn Thanh-hoa, the discovery of a s has to be reported to the horities, who appoint a commis n, composed of local and national r ernment representatives, which horises and supervises the ex itation of the tree. The commission rks the tree and, if necessary, sets uard over it to prevent any attempt dandestine barking.

Public auction

Tie discoverer is charged with the zesting, preparation and safe age of the bark. It is sold by lie auction, 50 per cent, of the its going to the discoverer, 30 per . to the village which provided guard and supervisor and 20 per . to the chief official of the ict, who is also a member of commission. The discoverer ins the bark from the small iches and the twigs which are of wer quality.

Nghe-an no such regulations y, and the finder of a tree has right to debark it whenever he •ses; frequently, however, he is >le, on account of poverty, to r the costs of harvesting and aration, and is obliged to apply a loan to a landowner or the authority; the lender thereby mes the owner of the tree and the auction of the bark, offers discoverer of the tree a pro on of the proceeds of the sale.

Economic necessity

trmally the tree is not barked it is at least 10 to 12 years old.

Mois do not harvest their trees they are 20 or 30 years of age, forest trees may be 40 to 50 old when they are discovered. >nomic necessity, however, imes compels the cultivator to J sell his trees when they are four or five years old, although recognised that bark from such > tre es is of inferior quality. >ark is usually cut in April-May n September-October, at which Is the bark lifts most easily and nest in essential oil, mger trees are barked earlier ; season than older ones. Trees ig wild in the forest may be

barked by the finder at any time, regardless of the season to prevent them falling into other hands.

Barking is usually carried out on the standing tree, starting with the main branches and working down the trunk. This is done, not by climbing the tree, but by erecting bamboo scaffolding around it. String is tied around the trunk and main branches at intervals of 16 in., and the bark cut through at these points with a sharp, pointed knife.

Vertical cuts are then made between the horizontal incisions, at intervals of 10 to 14 in., and the slabs of bark eased off with the aid of thin spatulas made of bamboo or buffalo horn. Each ring of bark is removed in this way until the bottom of the trunk is reached. The tree is then felled, after which the small branches and twigs are harvested.

In Nghe-an and Quang-nam it is usual first to remove a ring of bark at the base of the trunk, proceeding with the main operation after a period varying from a few days to a month.

The removal of this ring of bark arrests the flow of sap and makes the rest of the bark easier to remove. In some plantations the trees are left standing with suffcient bark on the trunk (from 1 ft to 4 ft above ground level) to give them a reasonable chance of survival.

Two forms

Preparation of the bark-. The bark is marketed in two forms—squared pieces, unscraped and unrolled (the pieces are actually gutter-shaped), and quills, which are often scraped.

The former, known as cane He plate or ban que, is used principally in China, whereas the quills, canelle roulee or dong que, are preferred in Western markets.

Although canelle plate is prepared exclusively from bark from the trunk and main branches, quills are obtained both from this type of bark and (principally) from the bark of the smaller branches.

Unrolled bark is subjected to much more elaborate processes of prepara tion especially in North Annam, than is that intended for quilling. In Thanh-hoa, for example, the bark is soaked in water for 24 hours, then washed and dried in the shade. . xt k then “fermented” for two days in closely woven bamboo baskets so u u ined w . ith dry hanana leaves that the bark is almost hermetically sealed. It is again washed and dried m the air and shade on bamboo screens, being wiped from time to time to remove mildew. (o ver)

Wien sufficiently dry, so that no re mildew forms, the bark is nd tightly on to pieces of thick iboo. Thus compressed, it assumes shape of the bamboo and becomes oth and polished. Twice daily, it mtied and wiped. This treatment s two weeks in the summer or a ith in the winter.

Preparation varies

tie method of preparation varies ifferent parts of the country. In e-an the pieces of bark, after the d washing and drying, are tied ther in pairs, and placed rontally in baskets of similar and shape. The baskets are ;d one on the other, separated layer of dried banana leaves, and lure is applied at the top by is of a large flat stone. ter three to seven days, accord to atmospheric conditions, the s of bark are removed from the Jts, immersed in water for an dried in the shade and then tied 0 bamboo tubes as described much simpler method is used uang-nam, where the pieces of are dried merely by spreading on a bamboo rack raised off round, and covering them with ia leaves. To prevent the pieces ark from rolling up, rods of 00, not quite as wide as the of the pieces of bark, are 1 transversely at top, middle and n, being held in place by the 1-over edges of the bark. When the bark is finished to the ements of the purchasers, the process taking a few days for bark, but up to a month for bark. nethod of fire-drying is used in n. The prepared bark is made 0 cylindrical bundles, each con 1 Pieces of approximately the length, wrapped round with a leaves and securely tied.

Assisted

ire of dry wood is lit at the i of a large hole dug in the 1, over which a bamboo m has been built, at such a that the flames will not reach this platform the bundles of re placed to dry. This method to be suitable for both wild iltivated bark.

Is are prepared from the bark riches which are no more than centimetres in diameter; the £d strips of bark are fre [ scraped to remove the value ter bark. Quill formation takes